Python script building a node tree works in command line and within django, but fails behind Apache
I realized that the blender background process did not read my blender preferences as normally it does when I launch as myself for background or for GUI:
# normally the following will spit out
Read prefs: /home/wr200m/.config/blender/2.91/config/userpref.blend

So I suppose when I sudo as any id outside of myself, blender does not know where to get my special setups. So I passed the $HOME env variable to sudo like this and voila.
$ sudo --preserve-env=HOME -u www-data /home/wr200m/software/blender-2.91.2-linux64/blender --background --python /home/wr200m/workspace/art/src/py/main/blender/blender/scene.py -- arg1 arg2
Blender 2.91.2 (hash 5be9ef417703 built 2021-01-19 16:16:34)
Read prefs: /home/wr200m/.config/blender/2.91/config/userpref.blend
found bundled python: /home/wr200m/software/blender-2.91.2-linux64/2.91/python

... SUCCESS ...

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